Feed for livestock typically includes different ingredients which are required to be mixed together before they are provided to the livestock. For example, hay may be mixed with a variety of feed supplements, such as vitamins, to provide a bulk feed material. Various mixers are known which are designed to mix the bulk feed material to a desired extent. Vertical feed mixers are disclosed, for instance, in U.S. Pat. No. 5,863,122 (Tamminga) and in U.S. Pat. No. 5,462,354 (Neier).
Many prior art vertical mixers include a container having one or more walls and a floor defining a mixing chamber having a general tub shape, with a mixing means, typically one or more augers, vertically positioned in the mixing chamber. In conventional use, the components of the bulk material are mixed together and cut by rotation of the auger. After mixing, the mixed bulk material is dispensed as appropriate from the mixer assembly via a door in the side of the mixing chamber.
Removal of the mixed bulk material is usually done in one of several methods. The mixed bulk feed material may exit the mixing chamber simply by opening the side door and allowing the rotation of the auger to force the mixed bulk food out through the door. This results in a very inconsistent unloading of the bulk material. As the auger rotates usually about once every 1.5 seconds, a high volume segment and a low volume segment of ejected bulk material is observed. This is because on each rotation of the auger, the bottom flight of the auger pushes out a large volume of bulk material as it passes the door which is preceded and followed by a low volume of ejected bulk material associated with the flight of the auger rotating through the rest of its travel before passing the open door on the next rotation. The net result is a series of bulk material clumps deposited from the vertical mixer assembly. To spread out the clumps, a conveyor may be attached to the vertical mixer. In this arrangement the mixed bulk material exits though the door of the mixing chamber and is deposited on the conveyor. The speed of the conveyor may then be varied to attempt to evenly deposit the mixed bulk material.
One problem with the mixer described above is the uneven distribution of the mixed bulk material. It is desirable, for many reasons appreciated in the art, to have an even distribution of bulk material. This is especially significant when the bulk material is feed. However, the addition of a conveyor to facilitate the even distribution of the bulk material is very costly, adds the problem of a complicated device to the mixer and requires a much higher degree of maintenance.
Another method providing a vertical mixer that more evenly ejects mixed bulk material requires an increase in power. This results in increased fuel or energy consumption and can result in an increase in noise, pollution and less longevity.
A need therefore exists for a vertical mixer assembly that more evenly unloads mixed bulk material without requiring more power or depending on a conveyor for even unloading.